an event resulting in great loss and misfortune
"the whole city was affected by the irremediable calamity"
"the earthquake was a disaster"
a state of extreme (usually irremediable) ruin and misfortune
"lack of funds has resulted in a catastrophe for our school system"
"his policies were a disaster"
a sudden violent change in the earth's surface
"The recent earthquake was nothing short of a catastrophe, leveling entire neighborhoods and reshaping the coastline in seconds."
any large and disastrous event of great significance
"The sudden collapse of the main bridge was a catastrophe that paralyzed traffic for miles across the entire region."